Combined effects of lead and edta on Na+,K+‐ATPase activity of erythrocyte membranes

This study focuses on the reaction of the membranes of erythrocytes based on the principles that use direct effects of infrasound. The effect on biological features was investigated through the experiments on the rats. The work determined the level of electrical conductivity of blood in rats during direct, indirect and combined effects of infrasound in vivo. There was found that infrasound stimulate the immune system and therefore the results recommend that caution is take place for people who are dealing with these low frequencies. There was used many different technologies and methods, including total differential count in order to consider all of the nuances of the observed object and the main goal. The exposure to infrasound caused increase in the electric conductivity of whole blood than the control in both types of exposure which indicates a large increase of the surface charge density of erythrocyte resulted from the formation of highly reactive species such as superoxide radicals. There were found some undesired biological effects, however further work could have decreased them to a lesser extent.

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Inhibition of Human Efflux Transporter ABCC2 (MRP2) by Self-emulsifying Drug Delivery System: Influences of Concentration and Combination of Excipients

Journal of Pharmacy & Pharmaceutical Sciences ◽

10.18433/j3vp5h ◽

2014 ◽

Vol 17 (4) ◽

pp. 447 ◽

Cited By ~ 9

Author(s):

Liang Li ◽

Tao Yi ◽

Christopher Wai-kei Lam

Keyword(s):

Drug Delivery ◽

Atpase Activity ◽

Cell Model ◽

Ultra Performance Liquid Chromatography ◽

Inhibitory Effect ◽

Combined Effects ◽

Efflux Transporter ◽

Peg 400 ◽

Efflux Ratio ◽

Liquid Chromatography Tandem Mass

PURPOSE: This study investigated influences of concentration and combination of excipients, commonly used in self-emulsifying drug delivery systems (SEDDS), on inhibition of human efflux transporter ABCC2 (MRP2). METHODS: Ten commonly used excipients of SEDDS with inhibitory effect on MRP2 including Cremophor® EL, Cremophor® RH, Pluronic® F127, Maisine® 35-1, β-cyclodextrin, Labrasol®, Pluronic® F68, PEG 2000, PEG 400 and Transcutol® were studied with the Caco-2 cell model. Six excipients with inhibitory effect including Cremophor® EL, Cremophor® RH, Pluronic® F127, PEG 2000, PEG 400 and Transcutol® were further analyzed using the MRP2 vesicle assay and ATPase activity assay. Ultra-performance liquid-chromatography tandem mass spectrometry was used to measure scutellarin as the MRP2 substrate. RESULTS: In studying concentration-dependent effects, five excipients including Cremophor® EL, Cremophor® RH, Pluronic® F127, Maisine® 35-1 and β-cyclodextrin showed concentration-dependent decrease in efflux ratio of scutellarin. The other five excipients did not show such phenomenon, and their inhibitory effects were restricted to be above to certain critical or minimum concentrations. In studying combined effects, PEG 2000 and Pluronic® F127 both showed combined effect with Cremophor® EL on inhibiting MRP2. However, some combinations of excipients such as PEG 400　and Transcutol® with Cremophor® EL increased the scutellarin efflux ratio and decreased the transport of scutellarin and ATPase activity, compared to Cremophor® EL alone. CONCLUSION: The above results suggest that appropriate choice of excipients according to their concentration-dependent and combined effects on MRP2 inhibition can facilitate formulation of SEDDS for improving the bioavailability of drugs that are MRP2 substrates. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

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Calcium-ATPase Activity in Cystic Fibrosis Erythrocyte Membranes: Decreased Activity in Patients with Pancreatic Insufficiency

Pediatric Research ◽

10.1203/00006450-198409000-00018 ◽

1984 ◽

Vol 18 (9) ◽

pp. 890-895 ◽

Cited By ~ 7

Author(s):

Dorr G Dearborn ◽

Robert J Wityk ◽

Lynelle R Johnson ◽

Louis Poncz ◽

Robert C Stern

Keyword(s):

Cystic Fibrosis ◽

Atpase Activity ◽

Pancreatic Insufficiency ◽

Calcium Atpase ◽

Erythrocyte Membranes

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Changes in Erythrocyte Membrane Ouabain-Sensitive Adenosine Triphosphatase after Renal Transplantation

Clinical Science ◽

10.1042/cs0480239 ◽

1975 ◽

Vol 48 (3) ◽

pp. 239-242 ◽

Cited By ~ 2

Author(s):

C. H. Cole ◽

R. Maletz

Keyword(s):

Renal Transplantation ◽

Atpase Activity ◽

Erythrocyte Membrane ◽

Adenosine Triphosphatase ◽

Inorganic Phosphorus ◽

Erythrocyte Membranes ◽

Healthy Controls ◽

Intracellular Electrolytes ◽

Transplant Patients ◽

The Mean

1. Intracellular electrolytes, and erythrocyte membrane adenosine triphosphatase (ATPase) activity, was studied in twenty patients after renal transplantation. 2. The mean ouabain-sensitive ATPase activity in the erythrocyte membranes of the transplant patients was 122 nmol of inorganic phosphorus (Pi) h−1 mg of tissue−1 (sem 14), compared with 62 nmol of Pi h−1 mg of tissue−1 (sem 8) in a group of paired, healthy controls. 3. The increase in ouabain-sensitive ATPase was most marked in the 4 months after transplantation. However, a significant increase in ouabain-sensitive ATPase persisted for more than 8 months after transplantation. 4. This increase in ouabain-sensitive ATPase was associated with a decrease in intracellular sodium in the erythrocytes of the transplant patients.

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Effect of a Hyperlipidic Diet on Lipid Composition, Fluidity, and (Na+-K+)ATPase Activity of Rat Erythrocyte Membranes

Membrane Biochemistry ◽

10.3109/09687688909025822 ◽

1989 ◽

Vol 8 (1) ◽

pp. 11-18 ◽

Cited By ~ 8

Author(s):

A. Bordoni ◽

P. L. Biagi ◽

G. Parenti Castelli ◽

S. Hrelia ◽

C. A. Rossi ◽

...

Keyword(s):

Atpase Activity ◽

Lipid Composition ◽

Erythrocyte Membranes ◽

Hyperlipidic Diet

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A protein activator of Mg2+-dependent, Ca2+-stimulated ATPase in human erythrocyte membranes distinct from calmodulin

Biochemical Journal ◽

10.1042/bj1870507 ◽

1980 ◽

Vol 187 (2) ◽

pp. 507-513 ◽

Cited By ~ 23

Author(s):

Douglas Mauldin ◽

Basil D. Roufogalis

Keyword(s):

Atpase Activity ◽

Sucrose Gradient ◽

Sodium Dodecyl ◽

Deae Cellulose ◽

Erythrocyte Membranes ◽

Dependent Manner ◽

Calmodulin Binding ◽

Heat Stable ◽

Protein Activator ◽

Human Erythrocyte Membranes

Treatment of extensively washed erythrocyte membranes with 0.1mm-EDTA decreased their Mg2+-dependent, Ca2+-stimulated ATPase [(Mg2++Ca2+)-ATPase] activity. An activator released by this treatment restored the (Mg2++Ca2+)-ATPase to its original value in a Ca2+-dependent manner. This activator was different from calmodulin, as determined by a number of criteria. It was retained on an Amicon XM-100 ultrafiltration membrane (molecular-weight cut-off 100000); it appeared in the void volume of Sephadex G-100 and G-75 columns; it was not retained on a DEAE-cellulose ion-exchange column at ionic strengths similar to those used to retain calmodulin; and it maximally activated (Mg2++Ca2+)-ATPase activity less than calmodulin and at a higher Ca2+ concentration. Like calmodulin, the activator is heat-stable. The activator fraction isolated on a 2.5–15% sucrose gradient in 0.16m-KCl showed a single band of mol.wt. 63000 and no calmodulin on 10%-polyacrylamide/sodium dodecyl sulphate gels. A trace amount of calmodulin was detected in the activator fraction by radioimmunoassay (approx. 10pg/ml of ‘ghosts’), but this amount was insufficient to account for the (Mg2++Ca2+)-ATPase activation. Furthermore, calmodulin-binding protein failed to inhibit (Mg2++Ca2+)-ATPase activity by more than 10–20% in the membrane preparations from which the activator was extracted. It was concluded that erythrocyte membranes contain a (Mg2++Ca2+)-ATPase activator that may attenuate the activation of the Ca2+-transport ATPase by calmodulin.

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